Karndean floor

[steve2]

I've had a Karndean floor installed and after 6 months noticed that marks appeared. Upon investigation it proved to be the pattern of cracks that had appeared in the levelling compound showing through. The existing floor is concrete, 2 inch sharp sand and cement screed and a skim of levelling compound. Onto this the installer put a layer of levelling compound and stuck the flooring onto this. The floor has central heating pipes embedded in it, they are insulated but still give out quite a lot of heat. The existing floor had been down for 15 years and prior to installation of the Karndean didn't have any obvious cracks. The top layer of compound is firmly bonded to the lower level. Has anyone experience this situation?

 

[DHTiling]

Hi steve and welcome..was the levelling compound latex based..?


you also might get more answers on our sister forum...Flooringadvice forum for floor layers. http://www.flooringadviceforum.com/index.php

 

[chrisroe]

if the original slc was a latex based product then the top layer also needed to be latex

do you know if the floor was primed before the top layer slc was put on ?

 

[bassman]

:welcome: To the forum :guitarist:

 

[Gazzer]

Hello and welcome

 

[steve2]

Not sure the product is UZIN NC 152. Perhaps you can answer this for me? Steve

 

[steve2]

I don't know what SLC was down originally and can't find out as it was 15 years ago. I believe it was primed and the Uzin NC 152 has bonded put cracks have now appeared

 

[chrisroe]

its a water based slc and one of the best out in the market so who ever did the job did not scrimp on materials which is good but it could mean deeper problems it is suitable for hot water heating systems so im afraid it needs a big of digging to find out

is it woodplank or tiles you have
do you have spare ones
where are you based

 

[White Room]

Hi and welcome

 

[Dan]

Welcome to tilersforums.com 🙂

 

[Bartlett]

:welcome: Hi and welcome

 

[jimbob]

:welcome::welcome:

 

[The Legend; Phil Hobson RIP]

:welcome::welcome:

 

[steve2]

It's woodplank. Yes we do have spares and we are in Southport, Merseyside

 

[Colour Republic]

Have you had to top up the heating system at all during this time?

 

[chrisroe]

gods country for golf have you done any digging ?

 

[CON5933]

Hi Steve, :welcome:
a few questions...
1, Is this in a conservatory?
2, was the ufh turned off well before the job (48hrs) and left off for at least the same after and then increased gradually...?
3, have you consulted Karndean direct?

 

[Diamond Pool Finishers]

hi :welcome:m8

 

[steve2]

No there is no leak.

 

[steve2]

No, if I did some digging what would I be looking for?

 

[steve2]

It's not a conservatory, the under floor heating was turned off and left off then introduced slowly. The floor was installed by PCS Flooring Formby, I wouldn't recommend them to anyone their service has been atrocious.

 

[tfs]

Hi mate,

It sounds to me that they have probably added too much water to the mix. Water mixes are usualy fast set and by adding too much water you will affect the setting times and more importantly reduce the durabilty long term.

You mentioned that the sand/ cement screed had previously been self levelled over, if this slc over the cement screed was not in a sound condition this may be another reason as to why the top layer of SLC has failed.

Are cracks run in lines or would you describe it more like circles/ patches?

 

[steve2]

Thanks for your comment. The pattern looks rather like mosaic when you look across the whole floor.

 

[tfs]

hi mate,

if it is like a grid/mosaic pattern then it sounds like the floor wasn't flat before or after the slc was done. As a result this raised patern is shadowing through your new floor. It is common when joints under Karndean have not been feather finnished and when any high/ low spots in the floor have not been grinded/ filled flat.

By the sound of it Im guessing that you may have had tiles down before and the residue on the floor was not removed or abraded to a flat finnish prior to instaling the slc.

If this is the case, the flooring contractor should realy have made sure that the surface was completly flat before fitting the floor.

 

[tfs]

sorry mate, just read your origonal post.

It sound to me like it may be the actual heating pipes in the screed that are appearing in the floor. your sand/ cement screed may not have been thick enough for the underfloor heating.

I may be wrong but I think your screed should be between 60-80mm in thickness with at least 40mm being above the under floor heating pipes. Some pumped screed can be applied at a thinner depth.

Even without UFH the screed should be at least 40mm in depth (this is what I was told at college)

 

[Time's Ran Out]

It's woodplank. Yes we do have spares and we are in Southport, Merseyside

:welcome: steve - I can see your problem - your from Merseyside and I always find scouscers are good for a 'crack' - sorry!